1. Field of the Invention
The present invention relates to plasma crucible sealing and a sealed plasma crucible.
2. Description of the Related Art
In our PCT/GB2008/003829, we have described and claimed a light source to be powered by microwave energy, the source having:                a solid plasma crucible of material which is lucent for exit of light therefrom, the plasma crucible having a sealed void in the plasma crucible,        a Faraday cage surrounding the plasma crucible, the cage being at least partially light transmitting for light exit from the plasma crucible, whilst being microwave enclosing,        a fill in the void of material excitable by microwave energy to form a light emitting plasma therein, and        an antenna arranged within the plasma crucible for transmitting plasma-inducing microwave energy to the fill, the antenna having:                    a connection extending outside the plasma crucible for coupling to a source of microwave energy;the arrangement being such that light from a plasma in the void can pass through the plasma crucible and radiate from it via the cage.                        
In that application, we gave the following definitions:
“lucent” means that the material, of which the item described as lucent, is transparent or translucent;
“plasma crucible” means a closed body [for] enclosing a plasma, the latter being in the void when the void's fill is excited by microwave energy from the antenna. In this application we continue to use the definition, with the proviso that it is in the context of sealing a crucible, which does not contain a plasma during sealing. Accordingly, as used herein, the definition includes the word “for”.
In this application, we define:
“filled plasma crucible” to mean a lucent plasma crucible having sealed in its void an excitable, light emitting fill.
A filled plasma crucible as such may have an antenna fixedly sealed within the crucible, possibly in the void, or a re-entrant in the crucible, into which an antenna is inserted for use of the crucible.